The water battery device has a sterilizing unit composed of a non-noble metal body and a noble metal body that are overlapped coaxially via an interval keeping member. The sterilizing unit is disposed in a passing water or flowing water or immersed in a stored water. Then, a battery action is generated via the water at a uniform clearance space between the non-noble metal body and the noble metal body. Thereby, metal ions are dissolved in a complete ionization state from the non-noble metal body, thereby giving sterilization effect to the water. A container has a container structure that generates an electric current in the water between the non-noble metal body and the noble metal body and that maintains an oxygen concentration in the water required to continually produce the battery action water. Moreover, with the container structure, the concentration of the battery action water produced between the non-noble metal body and the noble metal body becomes not less than a predetermined concentration at which an oxide film or biofilm is formed on a facing surface of the non-noble metal body. Thus, the container structure surrounds the non-noble metal body and the noble metal body to keep the concentration of the battery action water at the concentration not less than the predetermined concentration.